Grand Mount STL Wastewater Treatment Plant, Clinton County, Iowa

Grand Mount STL is a wastewater treatment plant located in Clinton County, Iowa, United States. It serves a small population of 619 residents, reflecting its role in a rural or small community setting. The plant is situated inland, away from coastal influences, and operates under the regulatory framework of the US Clean Water Act. The plant provides secondary treatment, which is a standard biological treatment process that removes biodegradable organic matter and suspended solids. With a designed capacity of 454.25 volume units and a current discharge volume of 302.83 volume units, the facility operates below its capacity, indicating room for future growth or seasonal variability. As a US plant, it is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the Iowa Department of Natural Resources, which set effluent limits to protect water quality. The treated effluent from Grand Mount STL is discharged into a local water body, likely a stream or river within the Mississippi River basin, as Clinton County is part of the Upper Mississippi River watershed. This discharge contributes to the overall water quality of the region, supporting aquatic life and downstream uses. The plant's operation helps protect the local environment from untreated wastewater pollution.

The plant discharges into a local water body that ultimately drains into the Mississippi River, a major waterway that flows into the Gulf of Mexico. The Mississippi River basin supports diverse aquatic ecosystems and is an important migratory corridor for fish and birds. The plant's secondary treatment helps reduce nutrient loads and organic pollution, contributing to the health of downstream waters.